Fluid motor

ABSTRACT

A FLUID MOTOR COMPRISING A GENERALLY DISC-SHAPED VALVE FORMED WITH A PLURALITY OF GROOVES AND KEYED FOR ROTATION WITH THE OUTPUT SHAFT TO CONTROL DISTRIBUTION OF FLUID TO AND FROM A PLURALITY OF DRIVE CYLINDERS CARRYING PISTONS WHICH DRIVE A WOBBLE PLATE TO ROTATE THE OUTPUT SHAFT. A NOVEL LOCK RING IS DIS-   CLOSED FOR RETAINING THE PISTONS IN ENGAGEMENT WITH THE WOBBLE PLATE, TOGETHER WITH A NOVEL PUMP SUPPLY AND LUBRICATION SYSTEM.

United States Patent 11 1 Van Wagenen et a1.

[11] 3,823,557 1451 July 16, 1974 FLUID MOTOR [76] Inventors: Norman L. Van Wagenen, 378 E.

Truman Ave., Salt Lake City, Utah 84115; Ara Norman Lamph, 540 N. 200 East, Bountiful, Utah 84010 22 Filed: Sept. 7, 1971 21 Appl. No.: 178,028

Related US. Application Data [60] Continuation-in-part of Ser. No. 740,414, May 23, 1968, which is a division of Ser. No. 607,428, Jan. 5, 1967, Pat. NO. 3,420,059.

[52] US. Cl 60/325, 60/327, 91/472,

91/499, 417/269 [51] Int. Cl. Fl6h 39/10 [58] Field of Search 60/53 A, 97 SE, DIG. 2,

[56] References Cited UNITED STATES PATENTS 3,016,837 1/1962 Dlugos 417/269 Johnston 91/499 Lambeth 91/499 FOREIGN PATENTS OR APPLICATIONS 557,167 2/1957 Italy 60/53 A Primary Examiner-Edgar W. Geoghegan Attorney, Agent, or FirmLynn G. Foster [57] ABSTRACT A fluid motor comprising a generally disc-shaped valve formed with a plurality of grooves and keyed for rotation with the output shaft to control distribution of fluid to and from a plurality of drive cylinders carrying pistons which drive a wobble plate to rotate the output shaft. A novel lock ring is disclosed for retaining the pistons in engagement with the wobble plate, together with a novel pump supply and lubrication system.

25 Claims, 19 Drawing Figures SRKU 02 0? H.

FEG.

PAIENEEB ml 1 61914 PAIENTED-RM sum 823 5 saw an or 11 FIG. 8

PATENIEB JUL 1 51974 sum mm 11% PATENTED T 31974 SHEET 'Bfi OF H FLUID MOTOR BACKGROUND Continuity cation, Ser. No. 607,428, filed Jan. 5, 1967 and issued Jan. 7, 1969, as U. S. Pat. No. 3,420,059.

FIELD OF INVENTION This invention relates to fluid motors and is particularly directed to novel constructions for fluid motors and methods of operating the same.

PRIOR ART In the past a great number of designs for fluid motors have been developed. Those of which the inventors are aware conventionally employ a rotating disc-type, kidney-shaped, sliding valve for sequentially actuating plural operating pistons which are used to drive the output of the motor. The output generaily will take the form of a wobble plate fixed to an output shaft, a crank shaft in combination .with a master rod, and so forth. The

problems with such fluid motors are several: firstly, seal junctures become unduly lengthy, thereby often necessitating the spring loading of the master disc valve to retain, as best as possible, the seal thereof during highpressure operation; secondly, the sliding nature of the master valve serves to produce a friction brake effect within the motor so as to reduce measurably the output torque of the motor; thirdly, seals in general are difficult to maintain; and fourthly, the sliding-disc, friction wear of such a valve means produces abrasion products and part wear which in time may interfere with the proper operation of the system.

As to the system proper, there apparently is yet absent from current, fluid motor system designs completely satisfactory provision for adapting the system to extraneous and/or inadvertently produced forces which serve to load unduly the fluid motor output shaft, or cause it to free-wheel, and thereby chance damage and- /or leakage of the equipment.

OBJECTS OF THE PRESENT INVENTION Accordingly, a principle object of the present invention is to provide a fluid motor exhibiting minimum friction loss, maximum output torque, and a maximum, fluid-pressure operating range.

A further object of the invention is to provide in a fluid motor a valving system, whether of pneumatic, hydraulic, or electrical character, and whether operated directly or remotely, which can easily be actuated to power sequentially the pistons of the fluid motor.

An additional object of the invention is to provide a balanced fluid motor drive system wherein fluid pressure return is positively driven in accordance with fluid input to the system, thereby insuring a closed-system effect and a balanced operation.

Another object of the present invention is to provide means for remotely controlling a fluid motor.

A further object of the present invention is to provide a fluid motor which is extremely compact.

Another object of the present invention is to provide portion of the motor.

An additional object of the present invention is to provide improved drive means for fluid motors.

A further object of the present invention is to provide improved lubrication means for fluid motors.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description, taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS 'FIG. 1 is a perspective view of a power transmission unit designed in accordance with the present invention and wherein the same comprises a turning unit for turning an external member such as a sign.

FIG. 2 is a vertical section of the fluid motor portion of the transmission and is taken along the line 2-2 in FIG. 1.

FIG. 3 is an enlarged, fragmentary section of a central portion of the fluid motor shown in FIG. 2.-

FIGS. 4 and 5 are section views, principally in schematic form, of single-winding and double-winding of solenoid control valves, respectively, which may be electrically activated for accomplishing the intake and exhaust functions hereinafter described.

FIGS. 6 and 7 are section views, principally in schematic form, and illustrate optionally-used control valves, either pneumatically or hydraulically operated, of the single-acting shuttle and double-acting shuttle types.

FIG. 8 is a schematic diagram of a representative control valve system of the present invention wherein each of the control valves takes a form as illustrated in F IG. 4.

FIG. 9 is an alternate system, shown in schematic form, of the control valve system of the present invention wherein each of the control valves is of the doublewinding type as shown in FIG. 5.

FIG. 10 illustrates in schematic form a control valve system wherein each of the control valves are hydraulically or pneumatically operated, the control valves themselves individually including respective, singleacting spools or gates in a manner as illustrated in FIG. 6.

FIG. 11 is a schematic representation of optional control valve system wherein each of the control valves is operated hydraulically, the individual valves themselves including valve spools which are double-acting as shown in FIG. 7.

FIG. 12 is a fragmentary vertical section of the principal portion of a fluid motor in accordance with another embodiment of the invention wherein kidneytype valving is used to actuate the several control valves successively for producing sequential powering of the fluid motor pistons.

FIG. 13 is an exploded perspective representation of the kidney valving and system operatively associated with the structure of FIG. 12.

FIG. 14 is a vertical section through an alternative form of the fluid motor of FIG. 1.

FIG. 15 is a side elevation view of the piston lock ring of the fluid motor of FIG. 14.

FIG. 16 is another side view of the lock ring of FIG. 15.

FIG. 17 is a plan view of the lower plate of the valve section of the fluid motor of FIG. 14.

FIG. 18 is a plan view of the annular ring and valve unit of the valve section of the fluid motor of FIG. 14.

FIG. 19 is a plan view of the upper plate of the valve section of the fluid motor of FIG. 14.

In FIG. 1 power transmission unit of the present invention may take the form of a turning unit including sign 11. However, such need not necessarily be the case. As will be understood from the discussion which follows, the invention basically takes the form of an improved power conversion and transmission unit.

Power transmission unit 10 includes a housing 12 which is provided with a pair of mounting plates 13 and 14. Bolted to mounting plate 13 is a power drive motor 15 which may be an electric motor supplied with input electric power cord 16. Disposed within housing 12 is a fluid pump 17 (pneumatic or hydraulic) which is provided with inlet 18 and inlet screen 19. These are shown merely in schematic view for purposes of illustration. The pump 17 will be driven by shaft 20 which, itself, is driven by the power drive motor 15 in the usual manner by the latters output shaft (not shown). The pump 17 will include a pressure side output 21 for supplying fluid under pressure to the fluid motor 22 which will be hereinafter described. The fluid motor 22 includes a pair of end-bells 23 and 24 which journal motor output shaft 25. The latter is coupled by suitable coupling 26 to sign 11 for rotating the same where this is desired.

FIG. 2 illustrates an over-all vertical section of the fluid pump motor utilized in the invention. The composite housing 12 includes respective end-bells 23 and 24, housing spacer ring 29, and inner and outer housing members 30 and 31. The inner housing member or block 30 includes a plurality of mutually spaced cylinder bores 32, arranged concentrically about the axis of shaft 25, and respective cylinder heads 33. Disposed in each of the cylinder bores 32 is a respective drive piston 34 having a spherical lower end 35. These latter abut pressure plate 36 of the wobble plate assembly 37. Wobble plate assembly 37 includes a wobble plate base 38, keyed at 39 to output shaft 25 and having retainer protuberance 38'. A pressure plate 36 is disposed over the wobble plate base 38, as indicated, and includes a plurality of cylindrical, load bearings 40 disposed therebetween. Side or radial bearings 41 are provided between the flange ring 42 of pressure plate 36 and the upper surface 43 of wobble plate base 38. A retainer spring or keeper 44 fits into a corresponding groove 45 of the pressure plate, as illustrated in more detail in FIG. 4. Oil seals 46 and 47 may take the form of 0- rings which are seated in corresponding grooves 49. These O-rings serve the function of oil seals, as does also O-ring 140 within shaft groove 141, and may be replaced by conventional glands; if desired.

As to shaft make-up relative to its journal bearings it is seen in FIG. 2 that a tapered journal bearing in the form of a Timken bearing 59 is seated on annular bear ing shoulder 49' and is retained in place by star lock washer 50 and nut 51, the latter being threaded on output shaft 25. The shaft 25 may include upper and lower shoulders 52 and 53 which serve as abutment surfaces for wobble plate base 38 and also the inner race 54 of lower journal bearing 55. The outer races 56 and 57 of the journal bearings and 59 abut the shoulders 40' and 60 as seen in the drawings. It will be understood that the lower surface 61 of wobble plate assembly 37 does not come in contact with upper surface 62 of the outer housing member 31. This is because the wobble plate structure is keyed for revolvement to the output shaft 25 by key 39 and rotates in accordance with rotation of the latter.

As to the cylinder block or inner housing 30, the same is shown to be provided with a plurality of parallel, mutually spaced cylinder bores 32 arranged in a ring concentric with the axis of output shaft 25, and a plurality of control valves 62 respectively fixedly disposed with respect to said cylinder bores and which are detailed individually in FIG. 3. Disposed above and communicating with the control valves is a manifold 64 the details of which will be shown hereinafter. Bolts 65 and 66 make up the assembled housing structure in the manner indicated. Bolts 67 secure the lower end-bell to the outer housing.

FIG. 3 illustrates the several cylindrical load bearings 40 as being retained in a bearing keeper 89. Wobble plate base 38 may include plural lightening holes and 91 for balancing the structure with respect to output shaft 25. Springs 90 may serve as compression springs for the pistons 34 and may be seated in annular grooves 91 of the individual cylinder heads 92. F IG.'3 also illustrates that the cam 82, keyed to shaft 25 by means of key 83, may be positioned in its chosen place by set screw 93, the latter being disposed within threaded bore 94 of the cam 82.

FIG. 3 illustrates the manifold 64 as comprising a pair of rings 95 and 96, the former including annular manifold grooves 97, 98 and the latter including a circular pattern of holes 100 and 101. The latter apertures communicate with apertures 78 and 79 of the valve body. The manifold ring structure may be secured in place to the valves by a plurality of bolts 102, one being shown. Inlet conduit 103 and outlet conduit 104 may be coupled to the pressure and exhaust manifold fittings P and B, respectively, as shown, in FIG. 3. The valve bodies themselves may be secured in place to the inner housing or block 30 by means of Allen screws 76. For most units the compression springs 90 will be utilized. It is possible, of course, for the spring to be deleted where the unitis to stand in an upright position so that gravity is effective to urge continuously the lower extremities of the power pistons 34 against the upper surface of pressure plate 36 of the wobble plate assembly.

FIG. 3 illustrates that the exhaust port at E is open relative to right-hand piston 34, and hydraulic fluid (or air under pressure) has been caused to proceed from the cylinder cavity shown on the right-hand side of the drawing upwardly through passageway 73 of valve gate 71 and through exhaust port E of the manifold to proceed out through conduit 104. At the time this is occurring the inlet or pressure port 96 and the alignment of valve gate passageway 73 of the left-hand side of the drawing will permit fluid to enter along path C into the cylinder chamber on the left-hand side of FIG. 3. This serves to thrust downwardly upon piston 34 so that the latter will advance the wobble plate assembly 37. Successive actuation of the pistons 34 through successive actuation of the control valves 62 in the manner indicated produces the revolvement of the wobble plate structure and the output shaft 25 keyed thereto.

For convenience the control valve 62 in the drawing shall be referred to as 62A-62D in FIGS. 4-7, respectively.

For the electrically operated, solenoid control valves in FIGS. 4 and 5 the electrical systems shown in FIGS. 9 and 8, respectively, will apply. The system of FIG. 9 incorporates a plurality of control valves 62A a's illustrated schematically in FIG. 4. Terminal X of each of the valves 62A is connected to a respective contact 142 of rotary switch 143. This may be a wafer switch including an insulative base 144 and a rotating, center conductive portion 145 including arcuate contactor segment 146. The contacts 142 will be respectively fixedly mounted to the base 144 in the conventional manner. All rotating switch members, e.g., member 145, remotely disposed or otherwise, will, be pivoted to base 144 and keyed through gear, shaft, or other means to output shaft 25 or to some others driving means. The arcuate contactor at 146 is preferably designed to be of sufficient extent that three of the contacts 142 (of'the light valve system) will be contacted at any one time. The contacting by the arcuate segment 146 with any of the contacts 142 will connect terminals X through conductive portion 145 to a source of, e.g. B+ potential at 147 through conductive wiper W. All of the terminals Y are maintained at a common reference (ground) potential. Thus, three of the solenoid valves 62A will be energized to on or pressure condition at any one time, whereas the remainder of the valves will remain unenergized. This, accordingly, produces a pressurization of the pistons 34, see FIG. 4, to engage the wobble plate assembly at its upper regions and thus to tend to rotate the latter about the axis of output shaft 25. As the switch 143 continues to rotate via conductive portion 145, the number of solenoid control valves 143 energized, though remaining equivalent, will nonetheless constitute a different and progressive set of control valves so that an effective circular pressurization of the wobble plate structure will be effected, through these several pistons 34 when pressured as previously indicated through the selective actuation of valves 62A. Where the valves 62A are not energized, then they will be in their exhaust condition.

Valves 628 in FIG. 8 individually correspond to the valve 628 illustrated in FIG. 5. This type of valve is a double-acting solenoid valve having a pair of windings provided with respect to terminals R, S, T, and U.

FIG. 8 represents schematically a system incorporating the control valve 628 of FIG. 5. Terminals T of each of the control valves are retained at a ground or common reference potential, as are also terminals S. Terminals U are electrically coupled by respective leads L to their respective contacts as indicated in FIG. 8. These contacts, labeled generically as V, are mounted to the insulative base 148 of rotating wafer switch 149. The latter includes a central, rotating, conductive member 150 having a contact wiping conductor segment 151. The latter contacts a group of three of the contacts (numbers 7, 8, and I being shown in FIG. 8) and, during its travel, contacts a progressing set of three contacts as the switch rotates. Ground potential is maintained at the circuit points indicated.

It is noted that representative terminal U of lowermost relay 62B is connected not only to contact member 5 on the wafer switch but also to terminal R of the relay 1628 at No. 8 position. Thus, when the solenoid winding associated with terminal U of the lowermost relay 62B is energized, through the movement of the wafer switch to contact the contact V at No. 5 position on the switch, then the opposite winding associated with the relay 623 at No. 8 position is electrically actuated to be disposed in the opposite condition. Thus, a single switch may accommodate both the energization of one set of relays into pressure condition while simultaneously energizing in the opposite direction three of the remaining control valves to discharge condition. The rotating center of the switch shown is keyed by gear shaft pin or other means to the output shaft 25 of the fluid motor. Thus, the rotation of the output shaft of the fluid motor simultaneously accomplishes a rotation of the central conductive portion of switch 149. This, in turn, produces a selective actuation of a set of three control valves 62B and an exhaust of three opposite control valves, so that the fluid motor continues to function in the manner indicated. The central portion of the switch is, of course, maintained at a B+ or other potential relative to the common reference potential indicated. Obviously alternating current solenoids and alternating current electrical sources may be used equally as well.

FIGS. 10 and 11 show hydraulic or pneumatic systems which may be employed equally as well to accomplish a progressive actuation of the control valves for selectively and sequentially pressuring the pistons of the fluid motor. In FIG. 10 the pump P and reservoir R are connected together as indicated schematically and are related to the several hydraulic or pneumatic lines [-1, in one embodiment of the invention, through a kidney-type valving means 155. For convenience of illustration only the rotating portion 156 of the kidney valve is illustrated. It will be understood that the same includes kidney-shaped openings 157 and 158, as illustrated. The portion 156 of member 156 may be keyed by gear or other means to the output shaft 25 of the fluid motor. This means is indicated schematically as 158. Solenoid valves 62C each include at their ports 127 a suitable connection (not shown) for a respective line H. The same will be understood to be in communicative relationship at areas H1 and H2 with such kidney porting as may pass thereover. The drawings illustrate the control valves 62C at positions Nos. 1, 2, and 3, which are in communicative relationship with the port opening 157. The latter is coupled by suitable manifold means 160 to pump P of the over-all transmission unit. Accordingly, the pump P will supply pressured fluid to the control valves for orienting the control valves to a pressured condition so that the latter may supply pressured fluid to the pistons of the fluid motor as aforementioned. In a corresponding manner, the three opposite control valves will be exhausted for their control fluid through kidney porting 158 and manifold 160' so that such fluid will be directed back to reservoir R. It is noted that a different set of three control valves will be supplied pressure fluid and, alternately, exhausted, as the kidney valve porting member 156 continues in its keyed rotation with its output shaft 145. Accordingly, there is provided a means, through the rotation of output shaft 25, itself, for porting the spring-loaded control valves 62C so that progressive sets of three are opened for pressuring the pistons of the fluid motor and, alternately, closed for returning the fluid within the fluid motor cylinders to the reservoir of the system.

FIG. 11 is substantially identical in operation to the system of FIG. 10. The control valves this time take the form of valve 62D wherein the spools thereof are double-acting as illustrated in FIG. 7. It is noted in FIG. 11 that the hydraulic leads H and I of the several valves communicate with kidney ports 161 and 162 of rotating kidney valve plate 163, of the composite kidney valve 164, the remainder of the parts of which are not illustrated for clarity of present illustration. Ports 165 and 166 are also included and assume selective conductivity with conduit I of the several control valves 62D. It will be understood that the extremities of the lines representing conduit H and I will become in conduction condition with any kidney port passing there-- over. Thus, the control valves in. the lower left-hand quadrant of the drawing are so disposed relative to the porting of kidney valve 164 that the H conduit supplies pressured fluid to the control valves, to urge the latter into a condition such that pressure fluid is passed therethrough to pressure the pistons within the several cylinders of the fluid motor. The fluid on the other side of the control valve cavities is returned through conduit I arid through kidney porting 165 to the reservoir R of the system. As the kidne' porting valve plate 163 continues its rotation, there 'will be a progressive and different set of three control valves energized for pressuring three of the fluid motor pistons, whereas the opposite three pistons will be able to exhaust through their effective control valves by virtue of the fluid of the auxiliary or driving system of the control valves being exhausted through porting 162 to the reservoir R.

It is noted in FIG. 11 that for the opposite sets of three control valves, i.e., disposed oppositely to each other, the first set of three is pressured as to one side and exhausted as to the remaining side, whereas the reverse condition is present with respect to the remaining set of control valves. This valve condition progressively rotates" in accordance with the rotation of the kidney-type valve disc 163. A suitably grooved or slotted manifold M1 and M2 (see FIG. 13) as appropriate for slide-type kidney valves. Intercouple the porting of the kidney valve with the pump and reservoir in the manner schematically illustrated.

It will be seen that the control systems of FIGS. 8-11 may be located remotely from the fluid motor controlled thereby and lend themselves to supervision by a computer or the like.

FIGS. 12 and 13 illustrate a central portion of a slightly modified fluid motor wherein two separate hydraulic or pneumatic systems are supplied, one to apply pressure to and receive exhaust from the pressure cylinders 34 in FIG. 4, and the remaining system to control the disposition of control valve spools 285. The individual spools may have extremities 286 and 287 which operate as stop abutments cooperating with internal and external rings 288 and 289 in the housing structure.

' In referring to FIG. 13 it is seen that the rotating kidney valve plate 290 includes annular passageway slots 291 and 292 and two pairs of kidney-shaped slots, i.e. 293, 293, 294 and 294.

Passageway 295 interconnects groove 292 with kidney slot 293. correspondingly, passageway 296 supplies intercommunication between kidney slot 294 and annular groove 291. In a similar manner passageway 297 provides communication between kidney slot 293 and annular groove 291. And passageway 298 supplies communication between annular groove 292 in kidney slot 294. The kidney slots illustrated are preferably approximately 150 in arcuate extent and are mutually opposite each other; thus, and assuming there are eight cylinders in the motor, three of the cylinders will be on pressure at any one particular time in the cycle, whereas the three opposite cylinders will be at exhaust condition. The annular rings 291 and 292 are simply manifold rings, with 291 being a pressure groove communicating through aligned passageways 300 to the pressure intake at 301. correspondingly, aligned passageways 302 offer communication between annular groove 292 and exhaust 303.

It is seen thatthtf: manifold ring .304 is provided with a plurality of holes 305 and 306 and also a pair of annular grooves 307 and 308 on the underside thereof.

Groove 308 communicates with alignedpassageways 309 to exhaust 310 of the other fluid system, whereas groove 307 communicates via passageway means 13 11 to the pressure side 31.2. I

The annular grooves 307 and 308 serve as manifold rings for system No. 1 which is a hydraulic or pn eurnatic system supplying pressure to and returning .ex-

haust from the pressure cylinders 34. In contrast, the

manifold grooves 291 and 292 of the rotating kidney valve supply hydraulic pressure for and return exhaust from the areas of the control valves approximate the outer ends of the valve spool 285. Thus, system No. 2 is a control system for controlling the movement back and forth of the various, mutually spaced, concentrically related spool valves, i.e., related to the axis of the output shaft 314.

As to make up of the remainder of the structure, the composite housing 315 includes the cylinder block 30A (correspondingly to cylinder block 30 in FIGS. 2 and 4), the outer housing 316 which corresponds with the outer housing of the structure in FIG. 2, and also an upper end .bell 317 which is bolted by bolts 318 to the remainder of the structure as'illustrated in FIG. 12. An oil seal 319 is mounted within'bell 317 to seal the rotating shaft 314. A pressure plate 320 is keyed by key 321 to shaft 314 and is locked in place by set screw 322. A plurality of spring seats take the form of counter bore areas 323 and are mutually spaced about the lower surface of the pressure plate 320. Springs 324 are mounted therein and are also mounted at the opposite extremities to spring seats 325 of the rotating kidney valve plate 326. Pins 327 and the pin springs 328 serve as a loose intercoupling means between the pressure plate and the rotating kidney valve plate.

In operation, the structure of FIGS. 12 and 13 functions substantially the same as the structure of-FIGS. l-4 previously described. By virtue of the annular groove and kidney passageways in the kidney valve plate, which rotates in accordance with the rotation of shaft 314, there is an alternate powering of opposite extremities of the shuttle valves 285 in FIG. 12 so that one of the valves admits pressure to the cylinder 32 (on the right) whereas the spool of an opposite control valve is translated in the opposite direction, so that fluid exhausted from the rising piston on the opposite side of the structure is caused to pass to the exhaust system. It is seen in FIG. 13 that annular groove 292 and kidney passageway 293 function with the exhaust, system No. 2, whereas the annular groove 291 and kidney passage 294' function on the pressure side. This allows for the progressive positioning of the control valve shuttles 285 to their pressure, and subsequently to their exhaust conditions as the shaft 314 and kidney valve 290 continue their rotation.

FIGS. 14-19 illustrate an alternative form of the fluid motor in which the spool valves are eliminated and a compact, self-lubricating, fluid motor is provided. As I seen in FIG. 14, the fluid motor, indicated generally at 2, comprises, a pump section, shown generally at 4, a valve section, shown generally at 6, and a drive section, shown generally at 8. The pump section 4 includes a two-stage pump 10' and a motor 12. The motor 12' serves to drive the pump 10 and may be any type of motor suitable for this purpose. The two-stage pump 10 may also be conventional. However, the pump shown and described in our aforementioned patent, U.S. Pat. No. 3,420,059, is preferred. The valve section 6 includes an upper plate 14', a valve plate 16', an annular ring 18 encircling the valve plate 16, and a lower plate 20. The valve section 6 functions to direct the flow of fluid between the pump section 4 and the drive section 8. The construction of the valve section 6 and the manner in which it performs this function will be described in detail hereinbelow.

The drive section 8 comprises a cylindrical head 22, preferably formed of aluminum or the like, provided with a plurality of internally threaded recesses 24' spaced uniformly about the head 22. The recesses 24 open at the bottom of head 22' and extend axially substantially through head 22'. A plurality of fluid conduits 26' are formed in head 22' and each communicates a respective one of the recesses 24 with the upper surface of head 22. A plurality of externallythreaded, annular inserts 28, preferably formed of steel or the like, are each threadedly secured in a respective one of the recesses 24 and project some distance below the bottom of head 22'. The inner walls 30' of the annular inserts 28 are smooth and form operating cylinders 32 for the floating pistons 34. The pistons 34' are each formed with a shank 36' which fits slidably within a respective one of the operating cylinders 32 and is formed with a head 38 having a radially projecting flange 40'. The upper cam following surface 42' and lower surface 44' of flange 40 are inclined, for reasons which will be explained below. It will be noted that lower surface 44' forms a blunt point, as seen at 45'. An output shaft 46' extends axially completely through the fluid motor 2 and is rotatably journalled in housing 48' of fluid motor 2, as by bearing 50'. A generally cylindrical sleeve 52' is keyed to the shaft 46 and is formed with an eccentric, inclined flange 54. A wobble plate 56' is rotatably mounted on the flange 54, as by bearing 58, and a lock ring 60, best seen in FIGS. 15 and 16, is keyed to shaft 46, as indicated at 62". The lock ring 60' is formed with a first inclined shoulder 64, which provides clearance for the wobble plate, and a second inclined shoulder cam surface 66, which overlies the flanges 40' of pistons 34 and serves to retain the pistons 34 in engagement with wobble plate 56'. The surface 68 (FIG. 15) of shoulder 66 which engages the flanges 40' is beveled, as indicated at 70 in FIG. 16, and the angle of the bevel varies from upper limit 72 to lower limit 74. Moreover, it should be noted that, at the limit points 72 and 74, surface 68 is not uniformly curved, but is formed with a blunt peak, as indicated at 76. It has been found that, if surface 68 were uniformly curved and surface 44 of pistons 34 were flat, the pistons 34 would tend to bind along such a uniform curve 68. However, this problem is overcome by forming surfaces 44 and 68 as described and shown herein. A reservoir of driving and lubricating fluid, such as oil, is disposed within housing 48', as indicated at 78', and four fluid conduits 80 and 86' extend completely through the drive section 8 and communicate the oil reservoir 78 with the valve section 6. Numeral represents a pair of closely spaced conduits which communicate with conduits 94 and 96 of lower plate 20 in FIG. 17. Similarly conduit 86 represents a pair of conduits which communicate with conduits 98 and 100' of lower plate 20 of FIG. 17. The purpose of these conduits will be described hereinafter.

As best seen in FIGS. l7, l8 and 19, the valve section 6 comprises upper plate 14, valve plate 16', annular ring 18, and lower plate 20. FIG. 17 is a plan view of lower plate 20 which, as seen in FIG. 14, is mounted on the upper surface of head 22' of drive section 8. The head 22, plates 14 and 20, and ring 18 are preferably secured together by bolts 88 which pass through apertures 90 in each of these components and are threadedly secured in suitable recesses, not shown, in the housing of the pump section 4. As seen in FIG. 17,

lower plate 20' is formed with a plurality of openings 92' extending therethrough which communicate the fluid conduits 26' of head 22' with valve plate 16. In addition, lower plate 20 is provided with passageways 94', 96', 98 and 100 extending therethrough. Drilled passageways 94', 96', 98' and 100 form extensions, respectively, of conduits 80, and 86', of FIG. 14. Conduits 98 and 100' are formed with ball seats 102 and 104 respectively, which form seats for ball valves 106 and 108.

FIG. 18 is a plan view of valve plate 16 and annular ring 18. Valve plate 16 is preferably of the type described in the copending application of Van Wagenen, et al., Ser. No. 175,853 filed Aug. 30, 1971, now U.S. Pat. No. 3,702,143, issued Nov. 7, 1972. As shown, valve plate 16 is generally disc-shaped, having an upper surface 1 10 and a lower surface 1 12. Both surfaces 110 and 112 are correspondingly formed and each have an inner circular recess 114, an outer circular recess 116, and a pair of substantially semi-circular recesses 118 and 120 disposed in opposing relation intermediate the circular recesses 114 and 116. Inner circular recess 1 14 is joined to semi-circular recess 118 by radial channels 122. Similarly, outer circular recess 116 is joined to semi-circular recess 120' by radial channels 124. A plurality of apertures 126 extend through valve plate 16 to communicate the corresponding recesses on the surfaces 110 and 112 of valve plate 16'. The semicircular recesses 118 and 120 of lower surface 112 communicate with the openings 92 of lower plate 20. Valve plate 16' has a central opening 128' which fits snugly about output shaft 46' and valve plate 16 is secured for rotation with output shaft 46 by suitable means such as key 130'. In addition, valve plate 16 is formed with a plurality of apertures 132 disposed about output shaft 46' to allow fluid passage through valve plate 16'. Annular ring 18' encircles valve plate 16 and is formed with fluid conduits I34 and 136 which communicate with conduits 94 and 96' of lower plate 20'. Ring 18 is also formed with apertures 138 and 140 which provide fluid communication with conduits 98 and 100 of lower plate 20 and serve to loosely retain ball valves 106 and 108. Finally, ring 18' is formed with a bore 142 extending radially therethrough which permits any fluid leaking between valve plate 16' and plates 14 and 20 to escape to the exterior of the valve section 6 to return to reservoir 78.

FIG. 19 is a top plan view of upper plate 14' of the valve section 6. As shown, upper plate 14' is formed with a first generally L-shaped recess 144 having one leg 146' connecting apertures 148 and 150 which extend through plate 14 and communicate with conduits 134 and 136 of ring 18'. The other leg 152 of recess 144' communicates with the inlet opening to the first stage pump of pump section 4. Pressurized fluid from the output side of the first stage pump of pump section 4 is applied to an oval recess 154 formed in plate 14. The oval recess 154 is connected by conduit 156 to a port 158' is formed on the underside of plate 14 and communicating with the outer circular recess 116 of valve plate 16. A plurality of apertures 160' extend through plate 14 and communicate oval recess 154 with aperture 138 of annular ring 18' and serve as a cover for ball valve 106. A second ball valve 162 is seated in a transverse bore 164' having a reduced diameter portion 166 which communicates with conduit 156 and forms a seat for ball valve 162. Ball valve 162 is urged into seat engaging position by compression spring 168. The outer end of bore 164 is internally threaded and receives an externally threaded plug 170 which is adjustable to vary the pressure applied by spring 168 to ball valve 162'. The plug 170 is secured in a desired adjusted position by set screw 172 in internally threaded bore 174 which intersects bore 164. Another bore 176 intersects bore 164 between ball valve 162 and plug 170 to permit fluid passing about ball valve 162 to be vented to the exterior of valve section 6 to return to the reservoir 78. A second generally L-shaped recess 178 is formed in plate 14' and a port 180 communicates the recess 178 with the inner circular recess 114 of valve plate 16. One leg 182 of recess 178 communicates with the inlet to the second stage pump of pump section 4, while the other leg 184 is provided with a plurality of apertures 186 which communicate with aperture 140 of annular ring 18 and serve as a cover for ball valve 108. A transverse bore 188 has a reduced diameter portion 190 which intersects recess 178 and serves as a seat for ball valve 192. Ball valve 192 is urged into seat engaging position by compression spring 194. The outer end of bore 188 is internally threaded and receives an externally threaded plug 196 which is adjustable to vary the pressure applied by spring 194 to ball valve 192. The plug 196 is secured in a desired adjusted position by set screw 198 in internally threaded bore 200 which intersects bore 188. Another bore 202 interrupts bore 188 between ball valve 192 and plug 196 and serves to permit fluid passing about ball valve 192 to be vented to the exterior of valve section 6 to return to the reservoir 78. A third generally L-shaped recess 204 communicates the outlet of the second stage pump of pump section 4 with the central opening 206 of plate 14'. Opening 206 of plate 14 corresponds to central opening 208 of lower plate 20 and openings 206 and 208 are dimensioned to circumscribe the apertures 132 of valve plate 16. Upper plate 14 is also formed with recesses 210 which communicate opening 206 with the exterior of the valve section 6.

In use, the motor 12' drives two stage pump Fluid from reservoir 78' is drawn through conduits 80 and 82 of drive section 8, conduits 94 and 96' of lower plate conduits 134 and 136 of ring 18', and apertures 148' and 150' and recess 144 of upper plate 14' to the inlet of the first stage pump of pump section 4. From the output of the first stage pump, pressurized fluid is supplied to oval recess 154 of upper plate 14 12 and passes through conduit 156 and port 158' to th outer circular recess 1 16 of upper surface 1 10 of valve plate 16. The pressurized fluid then flows through channels 124 to semi-circular recess and through apertures 126' to the corresponding recesses in lower surface 112 of valve plate 16 and, thence, through openings 92 of lower plate 20'. As indicated above, semi-circular recesses 118 and 120' of valve plate 16 communicate with conduits 26' of head 22 and, thus, with cylinders 32' of the drive section 8. It will be apparent that the semi-circular recesses 1 18 and 120 will communicate with the conduits 26' and cylinders 32 only on respective sides of the fluid motor 2. However, valve plate 16 is keyed to output shaft 46. Consequently, as output shaft 46' is rotated, valve plate 16' will be similarly rotated, causing the pattern of the cylinders 32' communicating with the respective semicircular recesses 118 and 120 to also be rotated. When pressurized fluid is supplied, through semi-circular recess 120, to the cylinders 32 on one side of fluid motor 2, the pistons 34' associated with these cylinders 32' will be driven downward against wobble plate 56, thereby rotating wobble plate 56 and output shaft 46. At the same time, the pistons 34 on the opposite side of'the fluid motor 2 will be driven upward by wobble plate 56 and will drive the fluid from the associated cylinders 32' through conduits 26 of head 22 to the semi-circular recess 118 of lower surface 108 of valve plate 16. The fluid will then pass through channels 122 to inner circular recess 114 and through apertures 126 to the corresponding recesses on upper surface 110 of valve plate 16. From the outer circular recess 114 of upper surface 110 of valve plate 16, the fluid will pass through port 180 and recess 178 of upper plate 14 to the inlet of the second stage pump of pump section 4. The output of the second stage pump passes. through recess 204 of upper plate 14' to the central opening 206 and flows through apertures 132 of valve plate 16 and central opening 208 of lower plate 20 about output shaft 46' to the reservoir 78'. This serves to lubricate output shaft 46 while returning the fluid to the reservoir 78' and provides a self-contained unit which is capable of operation at very low fluid levels. As indicated above, lock ring 60' serves to retain the pistons 34' in driving engagement with shaft 46 through wobble plate 56. Thus, free wheeling" of shaft 46 will tend to drive pistons 34 against the action of the fluid in cylinders 32 and will be prevented. Ball valves 162 and 192 constitute pressure relief valves which are actuated, if the fluid pressure in conduit 156 or recess 178 exceeds the pressure applied by springs 168 or 194, to vent the excess fluid through bores 176 or 202. Ball valves 106 and 108 are torque relief valves which are actuated, if the fluid pressure in recesses 154 or 178 falls below a predetermined value, to allow fluid from reservoir 78 to flow through conduits 86 in drive section 8, conduits 98 or 100' in lower plate 20, apertures 138 or in ring 18, and apertures or 186 in upper plate 14'. The function of ball valves 106, 108, 162' and 192 is described in detail in our aforementioned patent, US. Pat. No. 3,420,059.

Obviously, numerous variations and modifications may be made without departing from the present invention. Accordingly, it should be clearly understood that the forms of the present invention described above and shown in the accompanying drawings are illustrative only and are not intended to limit the scope of the present invention.

What is claimed is:

1. A fluid motor including, in combination, a housing, an output shaft journalled within said housing, a plurality of valve means having respective valve gates, cam means cooperable with said valve gates for sequentially actuating said valve gates, said cam means including a plurality of electrical switching circuits, a fluid pressure source, fluid supply means intercoupling said fluid pressure source to said valve means, fluid return means interposed between and intercoupling said valve means back to said fluid pressure source, said housing including mutually-spaced cylinders, a plurality of pistons respectively and operably disposed in said cylinders, said valve means being fixedly disposed in correspondence with corresponding ones of said cylinders for selectively supplying to, and subsequently exhausting from said cylinders, fluid pressure, said pistons including respective extensions protruding beyond said housing, a wobble plate affixed to said output shaft, said piston extensions engaging said wobble plate, said cam means, valve means, pistons, wobble plate and output shaft being mutually constructed and arranged such that sequential actuation of said valve means, as produced by the ultimate actuation thereof by said cam means during the latters revolvement, produces a corresponding sequential driving of said pistons so that said extensions of the latter rotate said wobble plate and, hence, said output shaft.

2. a fluid motor including, in combination, a housing, an output shaft journalled within said housing, a plurality of valve means having respective valve gates, cam means journalled upon said output shaft and cooperable with said valve gates for sequentially actuating said valve gates, gear means engaging said cam means for revolving the latter, and means for driving said gear means, a fluid pressure source, fluid supply intercoupling said fluid pressure source to said valve means, fluid return means interposed between and intercoupling said valve means back to said fluid pressure source, said housing including mutually-spaced cylinders, a plurality of pistons respectively and operably disposed in said cylinders, said valve means being fixedly disposed in correspondence with corresponding ones of said cylinders for selectively supplying to, and subsequently exhausting from said cylinders, fluid pressure, said pistons including respective extensions protruding beyond said housing, a wobble plate affixed to said output shaft, said piston extensions engaging said wobble plate, said cam means, valve means, pistons, Wobble plate, and output shaft being mutually constructed and arranged such that sequential actuation of said valve means, as produced by the actuation thereof by said cam means during the latters revolvement produces a corresponding sequential driving of said pistons so that said extensions of the latter rotate said wobble plate and, hence, said output shaft.

3. A fluid motor including, in combination, a plurality of cylinders, a plurality of pistons operatively disposed in said cylinders, a plurality of piston extensions secured to said pistons, respectively, and extending beyond said cylinders, an output shaft, means coupled to said shaft and co-acting with said piston extensions and responsive to the movement thereof for rotating said shaft, a source of pressurized fluid, said source having an input and an output, a plurality of control valve means separately connected to respective ones of said cylinders, intercoupling said cylinders to said output in one circuit branch and to said input in another circuit branch, and means for sequentially actuating said control valve means for sequential operation, whereby to actuate said rotating means comprising a kidney valve and means for driving said kidney valve.

4. A fluid motor including, in combination, a plurality of cylinders, a plurality of pistons operatively disposed in said cylinders, a plurality of piston extensions secured to said pistons, respectively, and extending beyond said cylinders, an output shaft, means coupled to said shaft and co-acting with said piston extensions and responsive to the movement thereof for rotating said shaft, a source of pressured fluid, said source having an input and an output, a plurality of control valve means separately connected to respective ones of said cylinders, intercoupling said cylinders to said output in one circuit branch and to said input in another circuit branch, and means for sequentially actuating said control valve means for sequential operation, whereby to actuate said rotating means and thereby revolve said shaft, said actuating means comprising a kidney valve keyed to said output shaft for rotation therewith, said fluid motor including a control circuit intercoupling said pressured fluid source through said kidney valve to said control valve means for altering the conductive condition of the latter.

5. A fluid motor comprising:

a housing,

an output shaft journalled in said housing,

a wobble plate non-rotatably secured to said shaft,

a plurality of fluid cylinders disposed uniformly about said output shaft,

a plurality of pistons each slidably mounted in a respective one of said cylinders and each having an enlarged head comprising a leading surface, which engages and drives said wobble plate, and a cam following surface,

a lock ring comprising a cam surface retaining the leading surface of the heads of said pistons immediately adjacent said wobble platethe cam following surfaces immediately engaging said cam surface whenever any piston head lifts from the wobble plate,

a fluid pump,

a motor connected to drive said pump, and

fluid distribution means connected to receive pressurized fluid from said pump and to distribute said pressurized fluid to appropriate ones of said cylinders to cause said pistons to drive said wobble plate.

6. A fluid motor comprising:

a housing,

an output shaft journalled in said housing,

a wobble plate non-rotatably secured to said shaft,

a plurality of fluid cylinders disposed uniformly about said output shaft,

a plurality of pistons each slidably mounted in a respective one of said cylinders and each having a head which engages and drives said wobble plate,

a lock ring retaining the heads of said pistons immediately adjacent said wobble plate,

a fluid pump,

a motor connected to drive said pump,

fluid distribution means connected to receive pressurized fluid from said pump and to distribute said pressurized fluid to appropriate ones of said cylinders to cause said pistons to drive said wobble plate,

the heads of said pistons being formed with a generally pointed surface to engage and drive said wobble plate on one side of the point of said surface and having a second surface inclined substantially equally but oppositely to said pointed surface, and

said lock ring having a surface to engage said second surface of said piston heads when the heads lift slightly from the wobble plate the lock ring surface extending generally annularly and somewhat parallel to the surface of said wobble plate.

7. The device of claim 6 wherein:

said surface of said lock ring forms a blunt peak adjacent the upper and lower limits of said surface.

8. The device of claim 5 further comprising:

a cylindrical head encircling said output shaft formed with a plurality of recesses disposed uniformly about said head and a plurality of fluid conduits each communicating a respective one of said recesses with a common surface of said head, and

a plurality of annular inserts each secured in a respective one of said recesses of said head with the interiors of said inserts defining said fluid cylinders.

9. The device of claim 5 further comprising:

a quantity of fluid disposed in said housing,

fluid intake means communicating said quantity of fluid with the intake to said fluid pump, and

discharge means discharging fluid from said pump about said output shaft to lubricate said shaft.

10. A fluid motor comprising:

a housing,

an output shaft journalled in said housing,

a wobble plate keyed to said shaft,

a plurality of fluid cylinders disposed uniformly about said output shaft,

a plurality of pistons each slidably mounted in a respective one of said cylinders and having a head engaging said wobble plate,

a lock ring retaining the heads of said pistons in engagement with said wobble plate,

a two stage fluid pump,

a motor connected to drive said pump,

fluid distribution means connected to receive pressurized fluid from said pump and to distribute said pressurized fluid to appropriate ones of said cylinders to cause said pistons to drive said wobble plate,

a quantity of fluid disposed in said housing,

fluid intake means communicating said quantity of fluid with the intake to said fluid pump,

discharge means discharging fluid from said pump about said output shaft to lubricate said shaft,

said fluid intake means being connected to the intake of the first stage of said pump,

said fluid distribution means being connected to receive fluid from the output of the first stage of said pump and to supply fluid to the input of the second stage of said pump, and

said discharge means being connected to the output of the second stage of said pump.

11. The device of claim 5 wherein: 65

said fluid distribution means comprises a generally disc-shaped valve member.

12. The device of claim 11 wherein:

said valve member is secured for rotation with said output shaft.

13. A fluid motor comprising:

a housing,

an output shaft journalled in said housing,

a wobble plate keyed to said shaft,

a plurality of fluid cylinders disposed uniformly about said output shaft,

a plurality of pistons each slidably mounted in a respective one of said cylinders and having a head engaging said wobble plate,

a lock ring retaining the heads of said pistons in engagement with said wobble plate,

a fluid pump,

a motor connected to drive said pump,

fluid distribution means connected to receive pressurized fluid from said pump and to distribute said pressurized fluid to appropriate ones of said cylinders to cause said pistons to drive said wobble plate,

said fluid distribution means comprises a generally disc-shaped valve member,

I said valve member having a surface formed with inner and outer circular recess and at least two semicircular recesses disposed in opposing relation with each of said semi-circular recesses connected to a respective one of said circular recesses.

14. The device of claim 13 wherein:

one of said circular recesses communicates with pressurized fluid from said pump,

the other of said circular recesses communicates with an input to said pump, and

said semi-circular recesses each communicate with a plurality of said cylinders.

15. A hydraulic fluid motor including, in combination, a housing, a right circular cylindrical output shaft journalled within and extending completely through said housing, a plurality of spool valve means comprising respective, translatable spool valve gates and respective cross-port valve bodies respectively slidably receiving said spool valve gates, cam means fixedly disposed upon said output shaft and cooperatively, operatively engaging said spool valve gates for sequentially translationally actuating said spool valve gates to alter the flow condition therethrough, a fluid pressure source of hydraulic fluid, fluid supply means intercoupling said fluid pressure source to said spool valve means for supplying said hydraulic fluid thereto, fluid return means including reservoir means interposed between and intercoupling said spool valve means back to said fluid pressure source for returning said hydraulic fluid as a supply therefor, said housing including mutually-spaced cylinders, a plurality of pistons respectively and operably disposed in said cylinders, said spool valve means being fixedly disposed in correspondence with corresponding ones of said cylinders for selectively supplying to, and subsequently exhausting from said cylinders, said hydraulic fluid, said pistons including respective extensions protruding beyond said housing, a wobble plate, a balanced wobble plate support member affixed to said output shaft and supporting said wobble plate, said piston extensions engaging said wobble plate, a recess formed in the inner end of each of said pistons, resilient means seated in said recesses and bearing against said housing to urge said piston extensions into engagement with said wobble plate, said cam means, spool valve means, pistons, wobble plate, and 

